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What is DAB digital radio?
Digital Audio Broadcasting (DAB) is one of digital radio technologies for broadcasting radio stations, used mainly in Europe. As in the case of digital terrestrial DVB-T that replaced over the years analog TV broadcasting, digital radio offers a range of benefits both for broadcasters and listeners.
Advantages of digital radio
- better sound quality, especially lack of noise
- good reception even in cars traveling at high speeds
- place for new broadcasters/programs
- ability to cover a whole country with a wide range of programs
- ability to use SFN networks (Single Frequency Network) - better coverage without the risk of interference
- better spectral and power efficiency
- automatic scanning and station detection (names) in receivers
- ability to upload additional content to the receivers, such as station name, program titles, texts of songs, images of record covers etc., information on traffic conditions
- a bridge to hybrid radio combining information received from broadcast stations and the Internet
Disadvantages of digital radio
- the positive difference in quality compared to analog broadcasting may not be noticeable to listeners - a lot depends on the emission parameters adopted by broadcasters
- additional costs for broadcasters - the analog FM equivalents will have to be continued for many years yet
- additional costs for listeners - they have to buy new receivers or at least new tuners
- lack of EU rules on the implementation of digital radio (each country should decide on its own whether to make the transition and, if so, technical details and schedule)
Frequency bands
DAB+ in Europe can use BIII/VHF (174 - 230 MHz - adopted in Poland) and L (1452 - 1492 MHz) bands. The BIII/VHF antennas are presented in the further part of the article.
The layout of T-DAB channels in BIII - 8 channels with a width of 7 MHz are divided into additional 4 "sub-channels." Each of the channels can contain from several to about ten radio programs. One of the channels is reserved for DVB-T.
T-DAB+ standard
T-DAB i.e. Terrestrial Digital Audio Broadcast is the name referring to the 300 401 standard developed by ETSI. This standard is currently used in most European countries that implement digital radio. T-DAB+ is an enhanced version of the standard (ETSI TS 102 563) and has been selected by Poland.
The encoding of the audio signal in DAB system is based on the MPEG-1 Audio Layer II standard ( ISO/IEC 11172-3), while the DAB+ version uses HE-AAC (AAC+) compression, which is twice as much effective.
The encoding of the audio signal in DAB system is based on the MPEG-1 Audio Layer II standard ( ISO/IEC 11172-3), while the DAB+ version uses HE-AAC (AAC+) compression, which is twice as much effective.
The maximum bit rate of a DAB/DAB+ multiplex in Poland is 2432 kbps (MSC Main Service Canal – 2304 kbps, FIC Fast Information Canal – 96 kbps). The rest of the bit stream and some part of the MSC are used for error correction.
It means that in practice, depending on the level of error correction, of the number of radio programs within a multiplex may range from 6 to 13 for the audio bit rate of 128 kbps and from 4 to 9 for the audio bit rate of 192 kbps.
It means that in practice, depending on the level of error correction, of the number of radio programs within a multiplex may range from 6 to 13 for the audio bit rate of 128 kbps and from 4 to 9 for the audio bit rate of 192 kbps.
Local information - not translated
Schedule of regular broadcasts in Poland
The components of the first DAB+ multiplex:
- 5 channels of Polish Radio (also available in analog form in FM band): Jedynka, Dwojka, Trojka, Czworka, Zagranica (international)
- Polskie Radio 24
- Radio Rytm
- Radio Regionalne
- in the future: Radio Eureka, Radio Retro, Radio Krasnal
| Stage | Date | Transmitters |
| 1 - orange | 01.10.2013 | Warszawa |
| Katowice | ||
| 2 - blue | 01.05.2014 | Gdańsk |
| Kielce | ||
| Kraków | ||
| Szczecin | ||
| Wrocław | ||
| 3 - green | 1.10.2014 | Łódź |
| Opole | ||
| Poznań | ||
| 4 - pink | 01.01.2015 | Bydgoszcz |
| Koszalin | ||
| Zielona Góra | ||
| 5 - yellow | 01.04.2015 | Białystok |
| Lublin | ||
| Rzeszów |
Antennas for the reception of analog FM broadcasts are not able to receive DAB+ transmissions, due to a different frequency band. The suitable antennas for digital radio operating in the BIII /VHF band are the same that are dedicated for the reception of terrestrial television in this band. However, since DAB+ radio is broadcast with vertical polarization (V), in most cases the antenna should be rotated 90 degrees in the vertical plane.
DAB+ antennas:
The suitable antenna cables are 75 ohm coaxial cables with high screening efficiency.
DAB/DAB+ receivers are equipped with IEC or F connectors. In every case the highest quality connections are guaranteed by the application of Cabelcon compression connectors. These connectors are characterized by high screening efficiency and self-compression feature - there is no need to use special tools.
DAB+ signals can be combined with other signals (analog FM radio, DVB-T) using antenna multiplexers with pass-band filters.
